Distributor cap electrode and cable termination

ABSTRACT

An internal combustion engine distributor cap has a high tension output electrode which is readily insertable in and removable from the distributor cap and serves also as a dependable electrical termination for an ignition spark plug cable.

United States Patent [191 Scott DISTRIBUTOR CAP ELECTRODE AND CABLE TERMINATION [75] Inventor: Ian J. C. Scott, Madison Heights,

Mich.

[73] Assignee: Chrysler Corporation, Highland Park, Mich.

[22] Filed: Jan. 10, 1973 [21] Appl. No.: 322,576

[52] US. Cl 339/223 S, 339/256 SP, 339/258 S [51] Int. Cl. H0lr 15/12 8"] F ihTf'S eai-cli 39/2231, 223 S125 6TSP, 339/258 S, 65, 66,186, 95 R 5'6 neteris' Cited UNlTED STATES PATENTS 2,785,387 3/1957 Batcheller 339/258 S Jan. 29, 1974 8/1965 Blanchenot 339/223 X 2,336,385 12/1943 Batcheller 339/256 SP 3,266,008 8/1966 Elliott 339/223 S FOREIGN PATENTS OR APPLICATIONS 1,802,590 5/1969 Germany 339/223 S Primary Examiner-Bobby R. Gay Assistant ExaminerRobert A. Hafer [571 .APV AVCT, V 7

An internal combustion engine distributor cap has a high tension output electrode which is readily insertable in and removable from the distributor cap and serves also as a dependable electrical termination for an ignition spark plug cable.

5 Claims, 10 Drawing Figures PATENTED JAN 2 9 I974 SHEET 2 0F 2 DISTRIBUTOR CAP ELECTRODE AND CABLE TERMINATION BACKGROUND OF THE INVENTION nally of the cap for sequential distribution of the high tension output energy of the ignition coil to the respective output electrodes. The latter are machined brass insert elements each having a depending electrode element at one end and an outwardly extending bored cylindrical socket at its other end for receiving a conductive ferrule termination on one end of a high tension cable extending between the distributor cap and a terminal post of a spark plug associated with a cylinder of the engine.

The use of a separate output electrode in the distributor cap and of a separate termination on the spark plug cable increases the expense and complexity of this portion of the ignition system and requires an electrical interconnection between the output electrode and the cable termination that is subject to possible contamination by dirt, oxidation, and moisture and to mechanical wear, deformation and misalignment.

The present invention seeks to provide and offers a combined distributor output electrode and ignition cable termination which eliminates the interconnection between the distributor output electrode and ignition cable, which is readily removable from and insertable in the distributor cap and which is of simple and inexpensive construction.

The manner of accomplishment of the above and other desiderata, together with the advantages and features of the invention, will appear from the following detailed description made with reference to the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical section view of a distributor employing the improved distributor cap output electrode and spark plug cable termination of the present invention;

FIG. 2 is a view of a fragmentary portion of the distributor of FIG. 1 with the distributor output electrode and ignition cable removed therefrom;

FIGS. 3 and 4 are details of portions of the distributor cap taken in the direction 3--3 and 44 of FIG. 2 with the output electrode and cable termination removed therefrom;

FIG. 5 is an enlarged perspective view of the combined distributor output electrode and ignition cable termination of the invention;

FIG. 6 is an enlarged'plan view of the stamping of which the distributor electrode and cable termination is formed; 1

FIGS. 7 and 8 are enlarged side elevation and top plan views, respectively, of the electrode terminal and cable termination;

FIG. 9 is an end view taken in the direction 9-9 of FIG. 8; and

FIG. 10 is an end view taken in the direction of 10-10 of FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the drawings, the subject distributor cap output electrode and ignition cable termination is illustrated in a distributor structure for an electronic ignition system as described in copending US. application Ser. No. 322,243 filed of even date and of common ownership herewith. It is contemplated, however, that 0 the output electrode and cable termination could be used with conventional distributor structures as well.

As shown in FIG. 1, the distributor 10 comprises a metallic, non-magnetic lower housing 34, an engine driven distributor shaft 36 extending through and journalled for rotation in the housing and a distributor cap 38 detachably mounted by spring clips 40 to the open upper end of the housing. Cap 38 is an inverted cupshaped member molded in one piece of dielectric insulating material, as a glass-filled alkyd resin, and has a dome-shaped crown portion 50 having a plurality of integrally formed, tubular frustro-conical tower-like projections 56 and 58 extending upwardly therefrom.

Tower 56, located axially centrally of the cap, has a brass insert terminal 82 molded therein, the upper end of which is adapted to receive a conventional snap-in ribbed connector terminal (not shown) on one end of an insulated cable from the secondary high-tension output side of the ignition coil. At its lower end the terminal 82 is swaged to a stationarydistribution ring element 44 having a plurality of equally angularly spaced, radial projecting finger-like elements 44a, which cooperate with the output electrodes 78 of the distributor and correspond in number to the number of engine cylinder spark plugs of the engine ignition system.

The output electrodes are received in a T-shaped opening as shown in FIG. 2 and extend axially through the bottom wall or floor 68 of each of the output towers 58, which are located outwardly of and are equally angularly spaced about the periphery of the distributor cap. The opening 70 extends into the interior of the distributor cap and is in registration alignment with a T-shaped dovetail slot 74 formed in the inner surface of the outer cylindrical wall 52 of the cap, as shown in FIG. 3. For ease of insertion and ready reten tion of the removable output terminal electrode 78, the outwardly located, flat back side 76 of the floor opening 70 and wall slot 74 is formed at a slight angle of about one or two degrees to the verticalas shown in FIG. 2.

The combination electrode and cable termination is a one-piece element formed of a flat, T-shaped brass stamping 100 shown in FIG. 5 as having a pair of oppositely laterallyextending arms 1 12, 114 and a longitudinally extending stem or blade portion.1 16 which is subsequently drawn and folded or pleated as in a progressive die, about its longitudinal axis of symmetry 102 to form a raised ridge portion 118. Arms 112, 114 form the split ferrule portion of the termination and are bent from the plane of the stamping as shown in FIG. 9 to form a trough-like or V-shaped pocket in which is received the ignition cable 80 from which the insulating material has been stripped back to expose the central current carrying core 81 thereof. The current carrying core 81 of the cable is folded back over the outer insulating sheath 83 and is received with the cable between the arms 112, 114, which are then crimped about the cable, firmly gripping and establishing electrical contact of the central current carrying core 81 with the terminal as shown in FIG. 5.

Blade portion 116 is of a substantially flat configuration and has an integrally formed raised ridge or rib portion 118 which is equidistantly located between the longitudinally extending sides 120, 122 and is shown as extending the entire length of the blade portion. The side edges of the blade portion adjacent the end thereof opposite the ferrule or cable gripping portion of the terminal are deflected slightly upwardly a few degrees out of the horizontal plane of the blade as shown in FIGS. 7 and 10, for ease of insertion and retention of the blade in the floor opening 70 and wall slot 74 in the distributor cap.

A conventional insulating boot 124 is slipped over the ignition cable and terminal assembly which is inserted into an output tower 58 of the distributor cap with the blade portion extending through the opening 70 and into the interior of the cap to a depth limited by a ledge 75 formed interiorly of the cap. The openings 70 in the floor of the output towers are aligned with the radially projecting electrodes 44a of the distributor ring element 44 so that the ridged portion 118 of the terminals 78 face opposite a corresponding one of the distribution ring electrodes 44a and is spaced therefrom by a uniform air gap. A cup-shaped shutter member 48, composed of dielectric insulating material and received on the end of the distributor shaft 36 for rotation thereby, has its cylindrical rim portion 58 extending into and intervening in the gap between the distributor electrodes 44 and the ridged portion 118 of the terminal. As described in the aforementioned application, the shutter 48 has an elongated slot 90 in its rim portion and prevents conductive association of the distribution electrodes with the output electrodes except where the shutter window 90 exposes a distribution electrode element to its oppositely located output electrode formed by the ridged portion of the terminal 78.

It will thus be seen that the present invention provides a simple, inexpensive and reliable termination for an ignition cable as well as a readily removable and insertable push-in pull-out output electrode for a distributor cap. ln contrast with current production forms of distributor caps in which the output electrodes are permanently affixed therein, should the subject output electrode be damaged, it can be readily replaced without replacement of the entire cap structure. The instant cable termination and output electrode eliminates the additional interconnection heretofore employed between the distributor output electrodes and ignition cable terminations, the combined functions of which are provided by the integrally formed, one-piece output electrode and cable termination which is adapted to be produced by simple stamping, folding, drawing and bending techniques;

Although the invention has been illustrated and described in a particular form of distributor structure used with electronic ignition systems, it can be employed in other forms of distributor structures without departing from the spirit and scope of the invention.

What is claimed is:

1. A combined push-in, pull-out distributor-output electrode and termination for a high voltage ignition cable adapted to be readily removably received in the cap of an automotive type ignition distributor having a high voltage distribution electrode therein, said electrode and cable termination comprising a unitary electrically conductive terminal element having a ferrule at one end adapted to be crimped about one end of said cable and an elongated blade portion of substantially flat spade-like configuration integral with and extending longitudinally in the direction of the axial extent of said ferrule and adapted to be received in a complementary shaped opening in the distributor cap forcooperation with the high voltage distribution electrode of said distributor, said ferrule being split in the direction of the axial extent thereof and said blade portion having a longitudinally extending, integrally formed raised rib on one face and intermediate the longitudinally extending sides thereof, said rib extending substantially the length of the blade portion so that the blade portion has a substantially T-shaped crosssectional configuration in a plane transverse thereto.

2. A distributor output electrode and cable termination in accordance with claim 1 wherein the ribbed end of the blade portion opposite the ferrule deflected slightly out of the plane of the blade portion.

3. The combination of a distributor output electrode and cable termination of claim 1 and a high voltage, low current insulated electrical ignition cable having an insulative covering surrounding a central current carrying conductive core from which the insulative covering has been stripped back to expose a length of the conductive core and the exposed length of the current carrying conductor is folded back over the outer surface of the insulative covering over substantially the entire axial length of the ferrule portion to contact the inner surface of the ferrule portion of the termination crimped about the ignition cable.

4. The combination of a distributor output electrode and a cable termination in accordance with claim 1 and a distributor cap for an automotive type ignition distributor having a high voltage distribution electrode therein and wherein the distributor cap has an axially extending opening therein of a shape complementary to that of the cross-section of the electrode portion of said termination and readily removably receiving the said electrode portion therein for cooperation with the distribution electrode of the distributor.

5. The combination recited in the claim 3 with a distributor cap for an automotive type ignition distributor having a high voltage distribution electrode therein and wherein the distributor cap has an axially extending opening therein of a shape complementary to that of the cross-section of the electrode portion of said termination and readily removably receiving the said electrode portiontherein for cooperation with the distribution electrode of the distributor. 

1. A combined push-in, pull-out distributor output electrode and termination for a high voltage ignition cable adapted to be readily removably received in the cap of an automotive type ignition distributor having a high voltage distribution electrode therein, said electrode and cable termination comprising a unitary electrically conductive terminal element having a ferrule at one end adapted to be crimped about one end of said cable and an elongated blade portion of substantially flat spade-like configuration integral with and extending longitudinally in the direction of the axial extent of said ferrule and adapted to be received in a complementary shaped opening in the distributor cap for cooperation with the high voltage distribution electrode of said distributor, said ferrule being split in the direction of the axial extent thereof and said blade portion having a longitudinally extending, integrally formed raised rib on one face and intermediate the longitudinally extending sides thereof, said rib extending substantially the length of the blade portion so that the blade portion has a substantially T-shaped crosssectional configuration in a plane transverse thereto.
 2. A distributor output electrode and cable termination in accordance with claim 1 wherein the ribbed end of the blade portion opposite the ferrule deflected slightly out of the plane of the blade portion.
 3. The combination of a distributor output electrode and cable termination of claim 1 and a high voltage, low current insulated electrical ignition cable having an insulative covering surrounding a central current carrying conductive core from which the insulative covering has been stripped back to expose a length of the conductive core and the exposed length of the current carrying conductor is folded back over the outer surface of the insulative covering over substantially the entire axial length of the ferrule portion to contact the inner surface of the ferrule portion of the termination crimped about the ignition cable.
 4. The combination of a distributor output electrode and a cable termination in accordance with claim 1 and a distributor cap for an automotive type ignition distributor having a high voltage distribution electrode therein and wherein the distributor cap has an axially extending opening therein of a shape complementary to that of the cross-section of the electrode portion of said termination and readily removably receiving the said electrode portion therein for cooperation with the distribution electrode of the distributor.
 5. The combination recited in the claim 3 with a distributor cap for an automotive type ignition distributor having a high voltage distribution electrode therein and wherein the distributor cap has an axially extending opening therein of a shape complementary to that of the cross-section of the electrode portion of said termination and readily removably receiving the said electrode portion therein for cooperation with the distribution electrode of the distributor. 